NEW YORK (Reuters Health) - Putting a television in a
child's bedroom may be setting them up for excess weight gain
over the next few years, suggests a new study.

Researchers found that children who slept in bedrooms with
TVs gained more weight each year over the next few years, than
kids without TVs in their rooms.

"It's well known that screen time is related to weight gain,
but we specifically wanted to look at whether televisions in the
bedroom are related to weight gain," Diane Gilbert-Diamond told
Reuters Health.

"We hypothesized that they would be because bedroom
television may disrupt sleep and there is a known link between
sleep disruption and weight gain," she added.

Gilbert-Diamond is the study's lead author from the Geisel
School of Medicine at Dartmouth College in Lebanon, New
Hampshire.

She and her colleagues write in JAMA Pediatrics that it's
estimated about a third of U.S. children and teens are
overweight or obese. Previous studies have also linked TVs in
children's bedrooms to an increased risk of being overweight.

The authors also note that about 71 percent of adolescents
have TVs in their bedrooms.

"We really hope to help our children get a healthy start in
life so that they have the best chance for a healthy future,"
Gilbert-Diamond said.

For the new study, she and her colleagues used data
collected from an ongoing study of U.S. teens.

About 6,500 kids between 10 and 14 years old were recruited
in 2003 to take a telephone survey. Those children and teens
also answered questions two years later and again four years
later.

"This is the first study to look at whether having a bedroom
TV led to future weight gain," Gilbert-Diamond said.

About 59 percent of participants reported having TVs in
their bedrooms.

Overall, the participants who reported having TVs in their
bedrooms had larger increases in their body mass index - a
measure of weight in relation to height - after two and four
years, compared to those who didn't have TVs in the bedroom.

The difference translates to about one extra pound of weight
gain each year among participants with bedroom TVs,
Gilbert-Diamond said.

While one additional pound each year may not seem like much,
she said those can add up throughout childhood.

"If a bedroom TV is present from an early age, it could lead
to substantial weight gain over the course of childhood,"
Gilbert-Diamond said.

The researchers acknowledge their study cannot say for sure
that bedroom TVs lead to sleep problems, which in turn lead
eventually to weight gain.

It might also be that participants with bedroom TVs were
exposed to more food advertising than those who didn't have TVs
in their bedrooms, for example.

"In the future, we'd like to explore other media devices -
such as laptops, tablets and smart phones - to see if they
relate to weight gain and to test whether bedroom media lead to
weight gain through disrupted sleep or other mechanisms,"
Gilbert-Diamond said.

For parents, she recommends taking the TVs from kids'
bedrooms.

"Unlike other parenting strategies that require persistent
monitoring and effort, removing a TV from a child's bedroom is a
one-time action," she said.